1. Field of the Invention
The present invention relates generally to suspensions for supporting read/write heads over recording media. In particular, the present invention is a head suspension assembly with a stacked coil tracking microactuator.
2. Description of the Related Art
Disk drives include suspensions for supporting read/write heads over information tracks of rotating disks. The well known and widely used Watrous-type suspensions include a load beam having a baseplate on a proximal end, a flexure on a distal end, a relatively rigid region adjacent to the flexure and a spring region between the baseplate and rigid region. An air-bearing slider which includes the read/write head is mounted to the flexure. The baseplate of the suspension is mounted to an actuator arm. A motor which is controlled by a servo control system rotates the actuator arm to position the read/write head over desired information tracks on the disk. This type of suspension is used with both magnetic or non-magnetic disks.
Disk drive manufacturers continue to develop smaller yet higher storage capacity drives. Storage capacity increases are achieved in part by increasing the density of the information tracks on the disks (i.e., by using narrower and/or more closely spaced tracks). As track density increases, however, it becomes increasingly difficult for the motor and servo control system to quickly and accurately position the read/write head over the desired servo track.
The use of suspensions having microactuators or fine tracking motors has been proposed to overcome these problems. One such suspension is disclosed in U.S. patent application Ser. No. 08/457,432 filed Jun. 6, 1995 (U.S. Pat. No. 5,657,188) by Jurgenson et al. entitled Head Suspension with Tracking Microactuator which is assigned to Hutchinson Technology Incorporated, the assignee of the present application.
There is, however, a continuing need for improved microactuators. In particular, the microactuator must be capable of quickly and accurately positioning the read/write head. The microactuator should also be lightweight to minimize detrimental effects on the resonance characteristics of the suspension, and relatively thin to enable close disk-to-disk spacing. It is also advantageous for the microactuator to operate off of relatively low voltage signals that do not interfere with read/write operations. To be commercially viable the microactuator must also be reliable and capable of being efficiently manufactured.